From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755675AbZCMNB1 (ORCPT ); Fri, 13 Mar 2009 09:01:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752679AbZCMNBQ (ORCPT ); Fri, 13 Mar 2009 09:01:16 -0400 Received: from hera.kernel.org ([140.211.167.34]:53952 "EHLO hera.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750910AbZCMNBP (ORCPT ); Fri, 13 Mar 2009 09:01:15 -0400 Date: Fri, 13 Mar 2009 13:00:29 GMT From: Peter Zijlstra To: linux-tip-commits@vger.kernel.org Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@redhat.com, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu Reply-To: mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, tglx@linutronix.de, mingo@elte.hu In-Reply-To: <20090313112300.927414207@chello.nl> References: <20090313112300.927414207@chello.nl> Subject: [tip:core/locking] sched: remove extra call overhead for schedule() Message-ID: Git-Commit-ID: e690e5337d953a0936a9735424a454ec21bae0a5 X-Mailer: tip-git-log-daemon MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.0 (hera.kernel.org [127.0.0.1]); Fri, 13 Mar 2009 13:00:32 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: e690e5337d953a0936a9735424a454ec21bae0a5 Gitweb: http://git.kernel.org/tip/e690e5337d953a0936a9735424a454ec21bae0a5 Author: Peter Zijlstra AuthorDate: Fri, 13 Mar 2009 12:21:26 +0100 Commit: Ingo Molnar CommitDate: Fri, 13 Mar 2009 13:55:17 +0100 sched: remove extra call overhead for schedule() Lai Jiangshan's patch reminded me that I promised Nick to remove that extra call overhead in schedule(). Signed-off-by: Peter Zijlstra LKML-Reference: <20090313112300.927414207@chello.nl> Signed-off-by: Ingo Molnar --- kernel/mutex.c | 4 +++- kernel/sched.c | 12 ++++-------- 2 files changed, 7 insertions(+), 9 deletions(-) diff --git a/kernel/mutex.c b/kernel/mutex.c index 5d79781..e1fb735 100644 --- a/kernel/mutex.c +++ b/kernel/mutex.c @@ -248,7 +248,9 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass, /* didnt get the lock, go to sleep: */ spin_unlock_mutex(&lock->wait_lock, flags); - __schedule(); + preempt_enable_no_resched(); + schedule(); + preempt_disable(); spin_lock_mutex(&lock->wait_lock, flags); } diff --git a/kernel/sched.c b/kernel/sched.c index 8549d48..01275cb 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -4543,13 +4543,15 @@ pick_next_task(struct rq *rq, struct task_struct *prev) /* * schedule() is the main scheduler function. */ -asmlinkage void __sched __schedule(void) +asmlinkage void __sched schedule(void) { struct task_struct *prev, *next; unsigned long *switch_count; struct rq *rq; int cpu; +need_resched: + preempt_disable(); cpu = smp_processor_id(); rq = cpu_rq(cpu); rcu_qsctr_inc(cpu); @@ -4606,15 +4608,9 @@ need_resched_nonpreemptible: if (unlikely(reacquire_kernel_lock(current) < 0)) goto need_resched_nonpreemptible; -} -asmlinkage void __sched schedule(void) -{ -need_resched: - preempt_disable(); - __schedule(); preempt_enable_no_resched(); - if (unlikely(test_thread_flag(TIF_NEED_RESCHED))) + if (need_resched()) goto need_resched; } EXPORT_SYMBOL(schedule);